DESCRIPTION: (Adapted from applicant's abstract.) In the primate two major parallel pathways, one involving the frontal eye fields and the other the posterior cortex and the superior colliculus, have been shown to be involved in the generation of visually guided saccadic eye movement. Recently another area has been implicated in visually guided eye movement control. This area, which resides in dorsomedial frontal cortex (DMFC), is unlike the frontal eye fields and the superior colliculus in that it appears to code saccadic eye movements utilizing a spatial coordinate system, a code that is capable of undergoing organization changes as a result of prolonged training on various eye-movement tasks. The purpose of the proposed work is to characterize the functional organization of DMFC; to establish how and to what extent this area is subject to organizational changes as a function of specific visually guided eye movement tasks; to determine how the area relates to the previously identified two parallel pathways of visually guided eye movement control; and to uncover what deficits arise in the execution of visually guided eye movements as a result of inactivation or damage to this area. Behavioral, physiological, lesion, anatomical, and modeling methods will be used to answer these questions. The work, which will be carried out in rhesus monkeys, whose visual and oculomotor systems are similar to that of man, should provide new understanding of the neural structures and neural circuits involved in the control of visually guided eye movements.